/*
 * ForRentDAO.java
 *
 * Created on March 28, 2007, 10:07 AM
 *
 * To change this template, choose Tools | Template Manager
 * and open the template in the editor.
 */

package edu.byu.isys413.samlam;

import java.sql.*;

/**
 * Extends the FeeDAO and handles database interaction for ForRent revenue source objects
 * @author Nick
 */
public class ForRentDAO extends PhysicalDAO{
    
    private static ForRentDAO instance;
    /** Creates a new instance of ForRentDAO */
    private ForRentDAO() {
        super();
    }
    
    //Singleton pattern
    public static synchronized ForRentDAO getInstance() {
        if (instance == null) {
            instance = new ForRentDAO();
        }
        return instance;
    }
    
    /////////////////////////////////
    ///   CREATE
    
    /**
     * There's no need for two creates because we don't need
     * a connection to create BOs.  We run the insert statement
     * later, when it get's saved for the first time.
     */
    public ForRent create() {
        ForRent forRent = null;
        try{
            String id = GUID.generate();
            forRent = new ForRent(id);
            Cache cache = Cache.getInstance();
            cache.put(forRent.getId(), forRent);
            
        }catch(Exception e){
            e.printStackTrace();
        }
        return (ForRent)forRent;
    }
    
    
    /////////////////////////////////////
    ///   READ
    
    /**
     * This is the public read statement.  It loads an existing record
     * from the database.
     */
    public synchronized ForRent read(String id) throws DataException {
        // check to see if id in the cache
        ForRent forRent = (ForRent)Cache.getInstance().get(id);
        if(forRent != null){
            // if so, return it immediately
            return (ForRent)forRent;
        }
        
        
        
        Connection conn = null;
        try {
            // retrieve a database connection from the pool
            conn = ConnectionPool.getInstance().get();
            // call read with a connection (the other read method in this class)
            forRent = ForRentDAO.getInstance().read(id, conn);
            
            // release the connection
            conn.commit();
            ConnectionPool.getInstance().release(conn);
            
        }catch (ConnectionPoolException e4){
            throw new DataException("Could not get a connection to the database.");
            
        }catch (SQLException e) {
            // rollback
            try{
                conn.rollback();
                ConnectionPool.getInstance().release(conn);
            }catch(SQLException e2){
                throw new DataException("Big error: could not even release the connection", e2);
            }catch (ConnectionPoolException e3){
                throw new DataException("Could not get a connection to the database.");
                
            }
            throw new DataException("Could not retrieve record for id=" + id, e);
        }
        
        // return object
        return forRent;
    }
    
    /**
     *  This is a package method that is called by the public read (above) or
     *  by another DAO.  Either way we already have a connection to the database
     *  to use.  The user (controller) code never calls this one directly, since
     *  it can't know about Connection objects or SQLExceptions.
     */
    public synchronized ForRent read(String id, Connection conn) throws SQLException, DataException {
        // check again if the id is in the cache, and if so,
        // just get it from the cache.  we need to check again
        // because this method might be called directly from
        // another DAO rather than from read above.
        ForRent forRent = (ForRent)Cache.getInstance().get(id);
        if(forRent != null){
            return forRent;
        }
        // if not in the cache, get a result set from
        // a SELECT * FROM table WHERE id=guid
        //query the database
        Statement stmt = conn.createStatement();
        ResultSet rs = stmt.executeQuery("SELECT * FROM ForRent WHERE forrentid = '"+ id + "'");
        
        
        if (rs.next()) {
        //call sets from the result set
        forRent.setId(rs.getString("id"));
        forRent.setTimesRented(rs.getInt("timesRented"));
        forRent.setCurrentRental(rs.getString("currentRental"));
        Cache.getInstance().put(forRent.getId(), forRent);
        super.read(rs.getString("id"), conn);
        
        forRent.setObjectAlreadyInDB(true);
        
        
        // save to the cache
        Cache.getInstance().touch(forRent.getId());
        stmt.close();
        }else{
            throw new DataException("Object was not found in the database.");
            
        }
        // return the BO
        return forRent;
    }
    
    //////////////////////////////////
    ///   UPDATE
    
    /**
     * This is the public save method.  It is what is called when
     * the user (controller) code wants to save or update an object
     * into the database.
     */
    public synchronized void save(ForRent forRent) throws DataException {
        Connection conn = null;
        try {
            // retrieve a database connection from the pool
            conn = ConnectionPool.getInstance().get();
            // call save with a connection (the other save method in this class)
            this.save((ForRent)forRent, conn);
            // release the connection
            conn.commit();
            ConnectionPool.getInstance().release(conn);
        }catch (ConnectionPoolException e4){
            throw new DataException("Could not get a connection to the database.");
        }catch (SQLException e) {
            // rollback
            try {
                conn.rollback();
                ConnectionPool.getInstance().release(conn);
            }catch (ConnectionPoolException e4){
                throw new DataException("Could not get a connection to the database.");
            }catch (SQLException e2) {
                throw new DataException("Big error: could not even release the connection", e2);
            }
            
            throw new DataException("Could not retrieve record for id=" + forRent.getId(), e);
        }
    }
    
    
    /**
     *  This is a package method that is called by the public save (above) or
     *  by another DAO.  Either way we already have a connection to the database
     *  to use.  The user (controller) code never calls this one directly, since
     *  it can't know about Connection objects or SQLExceptions.
     *
     *  By having other DAOs call this save method (rather than update or
     *  insert below, each DAO in a chained save (like the ForRentDAO calling
     *  MembershipDAO calling InterestDAO save chain) can independently decide
     *  whether to udpate or insert the BO it's saving.  That's why I made
     *  update and insert private rather than package level -- if you call
     *  them directly from another DAO, this DAO can't decide whether it's
     *  object needs to be inserted or updated.
     */
    synchronized void save(ForRent forRent, Connection conn) throws SQLException, DataException {
        // check the dirty flag in the object.  if it is dirty,
        // run update or insert
        if (forRent.isDirty()) {
            
            if (forRent.isObjectAlreadyInDB() == true) {
                update(forRent, conn);
            }else{
                insert(forRent, conn);
            }
            super.save(forRent, conn);
            // set the dirty flag to false now that we've saved it
            forRent.setDirty(false);
            
        }
        
        // touch the cache for the object
        Cache.getInstance().touch(forRent.getId());
    }
    
    /**
     * This method is really a part of save(bo, conn) above.  It could be
     * embedded directly in it, but I've separated it into it's own method
     * to isolate the SQL udpate statement and make it more readable.  But
     * logically, it's really just a part of save.
     */
    private synchronized void update(ForRent forRent, Connection conn) throws SQLException, DataException {
        // do the update statement
        Statement stmt = conn.createStatement();
        stmt.executeUpdate("UPDATE ForRent set forrentid='"+forRent.getId()+"', timesRented='"+forRent.getTimesRented()+"', currentRental='"+forRent.getCurrentRental()+"' WHERE lateID='"+forRent.getId()+"'");
        stmt.close();
    }
    
    /**
     * This method is really a part of save(bo, conn) above.  It could be
     * embedded directly in it, but I've separated it into it's own method
     * to isolate the SQL insert statement and make it more readable.  But
     * logically, it's really just a part of save.
     */
    private synchronized void insert(ForRent forRent, Connection conn) throws SQLException, DataException {
        // do the insert SQL statement
        Statement stmt = conn.createStatement();
        stmt.executeUpdate("INSERT INTO ForRent VALUES ('"+forRent.getId()+"', '"+forRent.getTimesRented()+"', '"+forRent.getCurrentRental());
        stmt.close();
    }
    
    
    ////////////////////////////////////
    ///   DELETE
    // we are not supporting because we never want to delete the ForRent from
    // our database.
    
    
    
    //////////////////////////////
    ///  SEARCH methods
    
    
}
